Tripping device.



C. B. KBNG, B. JACQBY & C. S. JOHNSON.

TRIPPVING DEVICE.

APPLICATION FILED MAY 28. 1911.

Patentfl Sept. 18, 191?.

2 SHEETS-SHED 2.

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CHARLES B. KING, BENJAMIN J'ACOBY, AND CHARLES S. JOHNSON, OF MARION, OHIO, ASSIGNORS TO THE MARION STEAM SHOVEL COMPANY, OF MARION, OHIO, A COR- PORATION OF OHIO.

TRIPPING DEVICE.

Specification of Letters Patent.

Patented Sept. 18, 1917.

To all whom it may concern:

Be it known that we, CHARLES B. KING, BENJAMIN JACOBY, and Ci-IARLEs S. JOHN- sox, citizens of the United States, residing at Marion, in the county of Marion and State of Ohio, have invented certain new and useful Improvements in Tripping Devices, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to tripping devices for excavating dippers and the like, and means for controlling the same.

The object of the invention is to provide a power operated device for tripping the dipper of an excavating mechanism to permit the load to be discharged therefrom; and to provide such a device with manually operated controlling means to cause it to be actuated to trip the dipper, and with automatic controlling means to interrupt the operation thereof after the dipper has been tripped, independently of the manually operated controlling means. It is also an object of the invention to provide such a device with means for applying thereto, between tripping operations, sutlicient power to control the tripping cable and to maintain the same taut without tripping the dipper. To accomplish these results it is a further object of the invention to provide an electrically operated tripping device having manually operated devices to close the circuit through the same and automatically operated devices to interrupt the same, and having means for supplying a small quantity of current to the device when said circuit has been interrupted. Other" objects of the invention will appear as the mechanism is described in detail.

In the accompanying drawings Figure l is a side elevation, partly broken away, of an excavating machine equipped .with our invention; Fig. 2 is a plan view of the forward portion of the supporting platform; Fig. 3 is a diagrammatical view of the tripping device, the controlling device therefor, and the circuits: and Fig. 4 is an enlarged detail view of the retarding device.

In these drawings we have illustrated one embodiment of the invention and have shown the same as applied to an electrically operated shovel which comprises a base 1 carried by trucks 2 and having mounted thereon a revolving platform 3 which carries the electrical devices for operating thevarious parts of the mechanism, and also carries the excavating devices. The excavating devices in the present machine comprise a boom at having mounted thereon a dipper arm 5 to the outer end of which is secured an excavating dipper 6. This dipper is provided with a hinged bottom 7 which is held normally in its closed position by means of a latch bar 8, with which is connected a trip arm 9. The tripping arm is preferably carried by the dipper arm and has connected thereto a cable 10 leading to the platform 3. -A pull on this cable will retract the latch bar 8, release the bottom of the dipper and permit the load to be discharged therefrom. This much of the mechanism is of standard construction and forms no part of the invention, it being shown for the purpose of illustrating the application of the invention thereto. It will be understood, however, that the utility of the inventionis not limited to an excavating mechanism of this particular kind, but it may be used with excavating devices of various kinds, which may bev operated by any suitable kind of power, and further, that the motor controlling devices to be herein described may be useful not only in controlling a dipper tripping device but in connec tion with devices of various kinds requiring a similar application of power.

In that embodiment of the invention here shown the dipper tripping device comprises a drum 11 to which is connected the tripping cable 10, and which is operably connected with the shaft of an electric motor 12, which is mounted on the platform 3. This motor may receive its current from any suitable source. If the mechanism is used in connection with an electrically operated shovel the electric motor 12 will receive its power from the same source as do the motors which operate the other mechanisms of the machine. If no source of electrical energy is available a generator may be provided, and, in the present instance, we have illus-' trated, diagrammatically, a generator 13 as the source of electrical current. The generator is connected with the motor by a suitable circuit, here shown as' comprising conductors 14 and 15. Interposed in this circuit adjacent to the generator is a manually operated switch 16, which is here shown as an ordinary knife switch and which serves to connect the motor and the controlling devices with, or disconnect the same from, the" generator. Preferably suitable fuses 17 are interposed in the circuit at the switch terminals. One side of the circuit, 14, leads directly from the generator, through the switch 16, to the motor. The other side of the circuit 15 has'interposed therein a circuit breaker and closer comprising a fixed contact member 18 and a movable contact member 19. This circuit breaker and closer' is under the control of the operator and when closed serves to complete the circuit from the generator through the motor. It is desirable that the tripping cable should be maintained taut and we have, therefore, provided means for supplying the motor with a limited amount of current when the circuit breaker 1819 is open, the amount of current so supplied being sufficient to develop. a slight torque in the motor shaft and thus rotate the drum to take up the slack in the cable and hold the same taut, but not suflicient to prevent the reverse movement of the drum when the movement of the dipper requires that the tripping cable be paid out. The amount-of current so delivered to the motor is so slight that the continued application thereof to the motor when the armature is stationary will not injure the motor. To accomplish this we have connected a suit able resistance 20 with the side of the main supply circuit on opposite sides of the circuit breaker and closer 1819. In the present arrangement resistance coils are connected by conductors 21- and 22 with the terminals of the contact members 18 and 19, respectively, of the circuit breaker and closer. When the circuit breaker and closer is open the circuit will pass through the resistance to the motor, but when the circuit breaker and closer is closed the circuit will followthe path of least resistance and pass through the contacts 18 and 19 to the motor. The circuit breaker and closer l8 and 19 is under the, control of the operator, but is not directly operated by him. A suitable electrically controlled actuating device is provided and a circuit therefor is led to a point adjacent tothe operators station, and provided with a switch which is readily accessible for manipulation by the operator. In the present construction the circuit breaker and closer is normally open. To this end the movable contact member 19 may be operated in any suitable manner, but, as here shown, it is so arranged that when free from control it will move by gravity to its open position. -Further,in the present arrangement, the contact member 19 -constitutes'the armature for an'electro-magnet 23, which is connected by a suitable circuit with the source of electric current and with the 'operators switch. As here shown this cir- 65 cuit comprises a conductor 24 leading from one end of the magnet coil to a movable member 25 of a second circuit breaker and closer, and-the fixed member 26 of this second circuit breaker and closer isconnec'ted by a conductor 27 with the conductor 14 of the main circuit, while the conductor 15 of the main circuit is connected by a conductor 28 with the operators switch. The other side of the circuit for the electro-magnet comprises a conductor 29 leading directly from that end of-the magnet coil opposite the end to which the conductor 24 is connected to the operators switch. The operators switch may be of any suitable character and may be mounted in any suitable position, but for convenience of operation it is here shown as comprising a push button 30 mounted in the end of: the controller handle 45 for the hoisting motor. This push button has connected therewith a plunger 31 arranged to engage the resilient contacts, 32 and 33, and close the circuit for the electromagnet. It will be apparent that when the push button 30 is depressed, the main switch 16 being closed, the electro-magnet 23 will be energized and the circuit breaker and closer 18 and 19 closed. As soon as this circuit is interrupted the magnet will be deenergized and the circuit breaker and closer will be opened, thus interrupting the main circuit and causing the current to travel through the resistance circuit to the motor.

It only requires a power impulse of short duration to actuate the drum 11 sufficiently to trip the dipper, and it Would be injurious to the motor if the full potential of the current was maintained across the terminals of the motor when the latter was stalled,

necessary, and this might very'readily result in serious injury to the motor. We have, therefore, provided means to automatically interrupt the main circuit after .1 an interval of time suflicient to permit the operation of the tripping device. To accomplish this we have provided means for automatically opening the circuit breaker 2526 in the circuit of the electro-magnet 23, thus deenergizing the magnet and permitting the circuit breaker 1819 to open independently of the switch 30. In the present construction the movable member- 25 of the circuit breaker 2526 is connected to one arm of a toggle 34, the other arm of which is connected to a fixed support. Connected with the toggle, at the joint thereof, is a rod 35 secured to and moving with the core 36 of a solenoid 37. This solenoid is connected by conductors 38 and 39 with the circuit of the electro-magnet and consequently the solenoid will be energized whenever the magnet 23 is energized, and the movement ofthe core 36 into'the coil of the solenoid will break the toggle and move the contact member out of contact with the member 26, thus breaking the circuit to the magnet 23. It will be noted, however, that the conductors 38 and 39 of the solenoid are connected with the electro-magnet circuit on opposite sides of the circuit breaker 2526. Hence the opening ofthe last-mentioned circuit breaker will not interfere with the flow of current through the solenoid but the latter will remain ener ized until the switch is released, thus retaining the circuit breaker and closer 2526 in its open position. In order to prevent the deenergizing of the electro-magieiet 23 and the opening of the main circuit fore the tripping device has fully operated we have provided a retarding device which will cause a slow movement to be imparted to the core of the solenoid,thus allowingan appreciable interval to lapse beforethe circuit breaker 2526 is opened. While this retarding device may be of variou kinds, it is here illustrated as comprising a dash-pot, or cylinder, 40, containing oil or other fluid, and having mounted therein a piston 41 connected with the core 36 of the solenoid, this connection being formed, in the present instance, by extending the rod beyond thelower end of the core and connecting the same with the piston within the cylinder 40. The piston is so constructed that the fluid will flow slowly from one side thereof to the other, thus permitting the piston to move only so fast as the oil escapes about the same. ,As here shown the piston is provided with one orv more ports, 42, through which the oil may escape, and this port, or ports, may be adjustable so that the speed at which the core of the solenoid moves may be regulated. The regulating device is shown as an aper- *'tured disk 43 mounted .on'the piston and adapted to have its aperture, or apertures,

' moved into more or less complete registration with the aperture, or apertures 1n the piston. Preferably the rod 35 is connected with the toggle 34 in such a manner that the movement of the toggle will not begin until the solenoid has partially completed its movement, thus avoiding a too slow drawing out of the movable member of the switch. In the present instance this is accomplished by a sliding connection between the rod 35 and the toggle, the movement of the rod relatively to the toggle being limited by stops 44.

The operation of the device has been fully described in connection with the several parts thereof and it will be apparent that e have p ovided an electrically operated device for tripping an excavating dipper which will maintain normally a flow of current of low value through the motor, which will control the slack in the tripping cable and will hold the same taut. The controlling mechanism may be manipulated by the operator to cause a rush of current through the motor to operate the same, but the duration of this flow of current through the motor is automatically controlled and is interrupted after a predetermined period of time.

While we have shown and described one embodiment of our invention we wish it to be understood that we do not desire to be limited to the details thereof as shown and described as various modifications will occur to a person skilled in the art.

Having now fully described our invention, what we claim. as new and desire to secure by Letters Patent,.is:

1. In an excavating machine, a frame, an excavating mechanism comprising a dipper having a hinged closure, a latch for controlling the movement of said closure, a cable connected with said latch, an actuatmg device mounted on said frame, connected with said cable and comprising a motor, a circuit for said motor, a circuit breaker and closer in said circuit,-means to close said circuit breaker and closer,'and means to automatically open the same.

2. In an excavating machine, a frame, an excavating mechanism comprising a dipper having a hinged closure, a latch for controlling the movement of said closure, a cable connected with said latch, an actuating device mounted on said frame, connected with said cable and comprising a motor, a circuit for said motor, a circuit breaker and closer in said circuit, means to close said circuit breaker and closer, and other means to automatically open said circuit breaker and closer after a predetermined period of time.

3. In an excavating machine, a frame, an excavating mechanism comprising a dipper having a hinged closure, a latch for controlling'the movement of said closure, a cable connected with said latch, an actuating device mounted on said frame, connected with said cable and comprising a motor, a

circuit for said motor, a circuit breaker and closer in said circuit, reslstance connected with said circuit on opposite sides of said are for said motor, a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, means for closing said circuit, and means controlled by the closing of the circuit through said magnet for interrupting said magnet circuit after an interval of time. p

5. In an excavating machine, a frame, an excavating mechanism comprising a dipper having a hinged closure, a latch for controlling the movement of said closure, a cable connected with said latch, an actuating device mounted on said frame, connected with said cable and comprising a motor, a circuit forsaid motor, a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, manuallyoperated means for closing said magnet circuit, a circuit breaker and closer in said magnet circuit, a solenoid having a core operatively connected with said circuit breaker and closer, said solenoid being connected intothe circuit of said electro-magnet on opposite sides of said circuit breaker and closer for said circuit,

whereby the solenoid will be energized s1- multaneously with said magnet and will remain energized after said magnet has been denergized.

6. In an excavating machine, a frame, an excavating mechanism comprising a dipper having a hinged closure, a latch for controlling the movement of said closure, a cable connected with said latch, an. actuating device mounted on said frame, connected with said cable and comprising a motor, acircuit for said motor, a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, manually operated means for closing said magnet circuit, a circuit breaker and closer in said magnet circuit, asol'enoid having a core operatively connected with said circuit breaker and closer, said solenoid being connected into the circuit of said elec-' tro-magnet on opposite sides of said circuit breaker and closer for said circuit, and means for retarding the movement of the core of said solenoid.

7. In a device of the character described, a drum adapted for connection with a. cable, means for applying power to saiddrum to actuate said cable and for applying power to said drum in reduced amount, between the operations thereof, to, take up the slack in said cable and hold the same taut.

8. Ina mechanism of the character described, a tripping device comprising a drum adapted for connection with a cable, means for applying power to said device to actuate said drum, means for automatically interrupting the application of power to said device, and means for continuing the application of power to said device in a lesser circuit through said magnet, a second circuit breaker and closer in said magnet circuit, a magnet connected with said magnet c1rcu1t on opposite sides of said second c1rcu1t breaker and closer, and an operative connection between said magnet and said second c1rcu1t breaker and closer.

10. In a mechanism of the character described, the combination witha motor and a circuit therefor,'of a circuit breakei' and closer in said circuit, an electro-magnet to operate said circuit breaker and closer, a circuit for said magnet, a switch to close the circuit through said magnet, a second circuit breaker and closer in said magnet circuit, a magnet connected with said magnet circuit on opposite sides of said second circuit breaker and closer, an operative connection between said magnet and said second circuit breaker and closer, and means to retard the opening movement of said second circuit breaker and closer.

11. In a mechanism of the character described, the combination with a motor and a circuit therefor, of a' circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, a switch for said circuit, and means controlled b said manually operated switch to automatically break the.

circuit through saidmagnet and to cause said circuit breaker and closer to be opened.

12. In a mechanism of the character described, the combination with a motor and circuit therefor, 'of a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a switch to control said magnet circuit, means controlled by said manually operated switch to interrupt said magnet circuit, and resistance connected with said first-mentioned circuit on opposite sides of the circuit breaker and closer therefor.

13. In a mechanism of the character described, the combination with a motor and circuit therefor, of a circuit breaker and closer insaid circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, a switch to close said magnet circuit, a second circuit breaker and closer in said magnet circuit, a solenoid connected with said magnet circuit on opposite sides of said last-mentioned circuit breaker and closer, and a connection between the core of said solenoid and the movable member of 'said last-mentioned circuit breaker and closer.

naa aaa 14. In a mechanism of the character de scribed, the combination with a motor and circuit therefor, of a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, a switch to close said magnet circuit, a second circuit breaker and closer in said magnet circuit, a solenoid connected withsaid magnet circuit on opposite sides of said last-mentioned circuit breaker and closer, a connection between the core of said solenoid and the movable member of said last-mentioned circuit breaker and closer, and means to retard the movement of said solenoid.

15. In a mechanism of the character described, the combination with a motor and circuit therefor, of a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, a switch to close said magnet circuit, a second circuit breaker and closer in said magnet circuit, a solenoid connected with said magnet circuit on opposite sides of said last-mentioned circuit breaker and closer, a connection between the scribed, the combination with a motor and circuit therefor, or a circuit breaker and closer in said circuit, an electro-magnet to close said circuit breaker and closer, a circuit for said magnet, a switch to close said magnet circuit, a second circuit breaker and closer in said magnet circuit, a solenoid connected with said magnet circuit on opposite sides of said last-mentioned circuit breaker and closer, a connection between the core of said solenoid and the movable member of said last-mentioned circuit breaker and closer, and resistance connected with the first-mentioned circuit on the opposite sides of the circuit breaker and closer therefor.

In testimony whereof, we afix our signatures hereto.

CHARLES E. KING. BENJAMIN JACQBY. (JHARLES S. JQHNSQN. 

